The present invention relates to integrated circuits (ICs) or integrated circuits used in receiving devices, which process signals from metadata, an Electronic Programming Guide (EPG), or an Interactive Programming Guide (IPG) for enabling/disabling/programming content control signals. More particularly, the invention relates to an integrated circuit in receiving devices, which include set top boxes, IPTV devices, cell phones, digital media extending devices, which receive video programs via a digital signal.
However, such content control signals have been circumvented by circumvention devices, commonly referred to as “black box” devices, which remove or attenuate the effects of positive and or negative pulses, while passing the (active field) program video intact. Such “black boxes” generally replace the negative (e.g., pseudo sync) and or positive going pulses (e.g. AGC pulses/signals) with a blanking level or with newly regenerated sync pulses free of pseudo sync/AGC signals.
A process disclosed in U.S. Pat. No. 4,631,603, John O. Ryan, December 1986, assigned to Macrovision Corporation, Santa Clara, Calif., incorporated by reference, is well known to have placed pseudo sync and AGC pulses in specific television (TV) lines for pre-recorded video home systems (VHS) tape and digital video disc (DVD) playback devices. These pseudo sync/AGC pulses inserted in a program video signal prohibit recording by affecting the AGC system of a recorder, while allowing (substantially) normal display of the program video signal. These added pulses, pseudo sync and or AGC pulses, have also been used for content control signals for personal video recorders, PVRs, or compliant devices that sense the added pulses and provides a command. However, the makers of the circumvention devices have observed the locations of the added pulses in the vertical blanking interval (VBI), and accordingly have generated a timing pulse to blank out or to modify at least some of the copy protection signals.
Several of the newer circumvention devices do away with conventional timing circuits and rely on microprocessors to provide the blanking pulses. Other circumvention devices utilize traditional timing circuits (e.g., retriggerable one shot) to locate the copy protection pulses.
Also, in the field adding pseudo sync pulses, these signals are usually hidden in a portion of the vertical blanking interval, which generally cause a small scanning error in the display device. But because most displays overscan the video information, which results in a cropped picture, the scanning error is generally not noticeable. However, with some displays with less overscan, a small but perceivable geometric distortion may be observed when certain anti-copy protection signals are applied in the vertical blanking interval.